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-ddump-types vs -fprint-explicit-foralls, and symbol-ness of worker/wrapper names [Re: [commit: ghc] master: Pretty-print the following TyThings via their IfaceDecl counterpart: * AnId * ACoAxiom * AConLike (065c35a) (fwd)]
by Dr. ERDI Gergo 17 Mar '14

17 Mar '14

I've just realized the original subject of this mail probably didn't properly highlight that this unearthed two issues that I'd like to hear opinions on, before going on to fix them. So here's my original mail: ---------- Forwarded message ---------- Date: Sun, 16 Mar 2014 00:50:19 +0800 (SGT) From: Dr. ERDI Gergo <gergo(a)erdi.hu> To: Joachim Breitner <mail(a)joachim-breitner.de> Cc: GHC Devs <ghc-devs(a)haskell.org> Subject: Re: [commit: ghc] master: Pretty-print the following TyThings via their IfaceDecl counterpart: * AnId * ACoAxiom * AConLike (065c35a) On Sat, 15 Mar 2014, Joachim Breitner wrote: > > Unexpected failures: > indexed-types/should_compile T3017 [stderr mismatch] (normal) > roles/should_compile Roles1 [stderr mismatch] (normal) > roles/should_compile Roles2 [stderr mismatch] (normal) > simplCore/should_compile T4306 [bad exit code] (normal) > th T8884 [stderr mismatch] (normal) > typecheck/should_compile tc231 [stderr mismatch] (normal) > https://s3.amazonaws.com/archive.travis-ci.org/jobs/20819762/log.txt > Are these related to your changes, and are pending fixing? (If not it > might take too long until we notice, and it will be more difficult to > find the cause.) Hi, Yes, these are related. However, they all point to just a change in the output format of -ddump-types so that by default, foralls are not printed. The old output format can be restored by passing in an extra -fprint-explicit-foralls flag. I think this is actually an improvement, and thus my suggestion is to simply update the expected output of these tests. The one interesting case is T4306 which fails because the generated name $wupd is regarded as an infix name, and thus with my new code is rendered as ($wupd) :: GHC.Prim.Double# -> GHC.Prim.Double# instead of the old $wupd :: GHC.Prim.Double# -> GHC.Prim.Double# I think this is actually a bug in isSymOcc, since I don't think the intention behind the generated name $wupd is to be regarded as an infix name. So we could change isLexVarSym so that if the first character is $, the rest is still checked for symbol-ness. If there's agreement on this, I'm happy to implement both changes. Bye, Gergo

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Re: [commit: ghc] master: Pretty-print the following TyThings via their IfaceDecl counterpart: * AnId * ACoAxiom * AConLike (065c35a)
by Johan Tibell 15 Mar '14

15 Mar '14

Could these changes be related to the validate failures I just posted about on the mailing list? On Thu, Mar 13, 2014 at 2:21 PM, <git(a)git.haskell.org> wrote: > Repository : ssh://git@git.haskell.org/ghc > > On branch : master > Link : > http://ghc.haskell.org/trac/ghc/changeset/065c35a9d6d48060c8fac8d755833349c… > > >--------------------------------------------------------------- > > commit 065c35a9d6d48060c8fac8d755833349ce58b35b > Author: Dr. ERDI Gergo <gergo(a)erdi.hu> > Date: Thu Mar 13 21:18:39 2014 +0800 > > Pretty-print the following TyThings via their IfaceDecl counterpart: > * AnId > * ACoAxiom > * AConLike > > > >--------------------------------------------------------------- > > 065c35a9d6d48060c8fac8d755833349ce58b35b > compiler/iface/IfaceSyn.lhs | 2 +- > compiler/iface/MkIface.lhs | 10 +++++++- > compiler/main/PprTyThing.hs | 59 > ++++++++++--------------------------------- > 3 files changed, 23 insertions(+), 48 deletions(-) > > diff --git a/compiler/iface/IfaceSyn.lhs b/compiler/iface/IfaceSyn.lhs > index 8ca8582..7484b37 100644 > --- a/compiler/iface/IfaceSyn.lhs > +++ b/compiler/iface/IfaceSyn.lhs > @@ -1100,7 +1100,7 @@ pprIfaceDecl (IfaceClass {ifCtxt = context, ifName = > clas, ifTyVars = tyvars, > sep (map ppr sigs)]) > > pprIfaceDecl (IfaceAxiom {ifName = name, ifTyCon = tycon, ifAxBranches = > branches }) > - = hang (ptext (sLit "axiom") <+> ppr name <> colon) > + = hang (ptext (sLit "axiom") <+> ppr name <> dcolon) > 2 (vcat $ map (pprAxBranch $ Just tycon) branches) > > pprIfaceDecl (IfacePatSyn { ifName = name, ifPatHasWrapper = has_wrap, > diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs > index 0af9af6..51df08c 100644 > --- a/compiler/iface/MkIface.lhs > +++ b/compiler/iface/MkIface.lhs > @@ -1461,7 +1461,7 @@ tyThingToIfaceDecl (AnId id) = idToIfaceDecl id > tyThingToIfaceDecl (ATyCon tycon) = tyConToIfaceDecl emptyTidyEnv tycon > tyThingToIfaceDecl (ACoAxiom ax) = coAxiomToIfaceDecl ax > tyThingToIfaceDecl (AConLike cl) = case cl of > - RealDataCon dc -> pprPanic "toIfaceDecl" (ppr dc) -- Should be > trimmed out earlier > + RealDataCon dc -> dataConToIfaceDecl dc -- for ppr purposes only > PatSynCon ps -> patSynToIfaceDecl ps > > -------------------------- > @@ -1477,6 +1477,14 @@ idToIfaceDecl id > ifIdInfo = toIfaceIdInfo (idInfo id) } > > -------------------------- > +dataConToIfaceDecl :: DataCon -> IfaceDecl > +dataConToIfaceDecl dataCon > + = IfaceId { ifName = getOccName dataCon, > + ifType = toIfaceType (dataConUserType dataCon), > + ifIdDetails = IfVanillaId, > + ifIdInfo = NoInfo } > + > +-------------------------- > patSynToIfaceDecl :: PatSyn -> IfaceDecl > patSynToIfaceDecl ps > = IfacePatSyn { ifName = getOccName . getName $ ps > diff --git a/compiler/main/PprTyThing.hs b/compiler/main/PprTyThing.hs > index 27e7390..fb92b5a 100644 > --- a/compiler/main/PprTyThing.hs > +++ b/compiler/main/PprTyThing.hs > @@ -23,20 +23,18 @@ module PprTyThing ( > ) where > > import TypeRep ( TyThing(..) ) > -import ConLike > import DataCon > -import PatSyn > import Id > import TyCon > import Class > -import Coercion( pprCoAxiom, pprCoAxBranch ) > +import Coercion( pprCoAxBranch ) > import CoAxiom( CoAxiom(..), brListMap ) > import HscTypes( tyThingParent_maybe ) > -import HsBinds( pprPatSynSig ) > import Type( tidyTopType, tidyOpenType, splitForAllTys, funResultTy ) > import Kind( synTyConResKind ) > import TypeRep( pprTvBndrs, pprForAll, suppressKinds ) > import TysPrim( alphaTyVars ) > +import MkIface ( tyThingToIfaceDecl ) > import TcType > import Name > import VarEnv( emptyTidyEnv ) > @@ -44,7 +42,6 @@ import StaticFlags( opt_PprStyle_Debug ) > import DynFlags > import Outputable > import FastString > -import Data.Maybe > > -- > ----------------------------------------------------------------------------- > -- Pretty-printing entities that we get from the GHC API > @@ -76,7 +73,7 @@ pprTyThingLoc tyThing > > -- | Pretty-prints a 'TyThing'. > pprTyThing :: TyThing -> SDoc > -pprTyThing thing = ppr_ty_thing showAll thing > +pprTyThing thing = ppr_ty_thing (Just showAll) thing > > -- | Pretty-prints a 'TyThing' in context: that is, if the entity > -- is a data constructor, record selector, or class method, then > @@ -88,7 +85,7 @@ pprTyThingInContext thing > where > go ss thing = case tyThingParent_maybe thing of > Just parent -> go (getName thing : ss) parent > - Nothing -> ppr_ty_thing ss thing > + Nothing -> ppr_ty_thing (Just ss) thing > > -- | Like 'pprTyThingInContext', but adds the defining location. > pprTyThingInContextLoc :: TyThing -> SDoc > @@ -100,21 +97,17 @@ pprTyThingInContextLoc tyThing > -- the function is equivalent to 'pprTyThing' but for type constructors > -- and classes it prints only the header part of the declaration. > pprTyThingHdr :: TyThing -> SDoc > -pprTyThingHdr (AnId id) = pprId id > -pprTyThingHdr (AConLike conLike) = case conLike of > - RealDataCon dataCon -> pprDataConSig dataCon > - PatSynCon patSyn -> pprPatSyn patSyn > -pprTyThingHdr (ATyCon tyCon) = pprTyConHdr tyCon > -pprTyThingHdr (ACoAxiom ax) = pprCoAxiom ax > +pprTyThingHdr = ppr_ty_thing Nothing > > ------------------------ > -ppr_ty_thing :: ShowSub -> TyThing -> SDoc > -ppr_ty_thing _ (AnId id) = pprId id > -ppr_ty_thing _ (AConLike conLike) = case conLike of > - RealDataCon dataCon -> pprDataConSig dataCon > - PatSynCon patSyn -> pprPatSyn patSyn > -ppr_ty_thing ss (ATyCon tyCon) = pprTyCon ss tyCon > -ppr_ty_thing _ (ACoAxiom ax) = pprCoAxiom ax > +-- NOTE: We pretty-print 'TyThing' via 'IfaceDecl' so that we can reuse > the > +-- 'TyCon' tidying happening in 'tyThingToIfaceDecl'. See #8776 for > details. > +ppr_ty_thing :: Maybe ShowSub -> TyThing -> SDoc > +ppr_ty_thing mss tyThing = case tyThing of > + ATyCon tyCon -> case mss of > + Nothing -> pprTyConHdr tyCon > + Just ss -> pprTyCon ss tyCon > + _ -> ppr $ tyThingToIfaceDecl tyThing > > pprTyConHdr :: TyCon -> SDoc > pprTyConHdr tyCon > @@ -143,10 +136,6 @@ pprTyConHdr tyCon > | isAlgTyCon tyCon = pprThetaArrowTy (tyConStupidTheta tyCon) > | otherwise = empty -- Returns 'empty' if null theta > > -pprDataConSig :: DataCon -> SDoc > -pprDataConSig dataCon > - = ppr_bndr dataCon <+> dcolon <+> pprTypeForUser (dataConUserType > dataCon) > - > pprClassHdr :: Class -> SDoc > pprClassHdr cls > = sdocWithDynFlags $ \dflags -> > @@ -158,28 +147,6 @@ pprClassHdr cls > where > (tvs, funDeps) = classTvsFds cls > > -pprId :: Var -> SDoc > -pprId ident > - = hang (ppr_bndr ident <+> dcolon) > - 2 (pprTypeForUser (idType ident)) > - > -pprPatSyn :: PatSyn -> SDoc > -pprPatSyn patSyn > - = pprPatSynSig ident is_bidir args (pprTypeForUser rhs_ty) prov req > - where > - ident = patSynId patSyn > - is_bidir = isJust $ patSynWrapper patSyn > - > - args = fmap pprParendType (patSynTyDetails patSyn) > - prov = pprThetaOpt prov_theta > - req = pprThetaOpt req_theta > - > - pprThetaOpt [] = Nothing > - pprThetaOpt theta = Just $ pprTheta theta > - > - (_univ_tvs, _ex_tvs, (prov_theta, req_theta)) = patSynSig patSyn > - rhs_ty = patSynType patSyn > - > pprTypeForUser :: Type -> SDoc > -- We do two things here. > -- a) We tidy the type, regardless > > _______________________________________________ > ghc-commits mailing list > ghc-commits(a)haskell.org > http://www.haskell.org/mailman/listinfo/ghc-commits >

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Arrow notation vs RebindableSyntax
by Nicolas Frisby 15 Mar '14

15 Mar '14

The 7.8-rc2 User Guide for rebindable syntax includes: Arrow notation (see Section 7.16, "Arrow notation ") uses whatever arr, > (>>>), first, app, (|||) and loop functions are in scope. But unlike the > other constructs, the types of these functions must match the Prelude types > very closely. Details are in flux; if you want to use this, ask! I want to use this: my types for the functions apparently do not match the Prelude types closely enough. Whom should I ask about this? Thanks very much. -Nick ----- Further Context If I do something similar with Monad and RebindableSyntax, it type-checks. I'm doing some experimentation for work. I'd like to index my arrows as follows. (Disclaimer: I have not yet considered any of the laws; I do not currently intend to support `app' and |||.) infixr 1 >>>, <<< type family (:*:) (i :: Maybe *) (j :: Maybe *) :: Maybe * type instance Nothing :*: j = j type instance i :*: Nothing = i type instance Just i :*: Just j = Just (i,j) returnA :: IArrow arr => arr Nothing a a returnA = arr id -- second, ***, and &&& can have the standard default definitions class IArrow (arr :: Maybe * -> * -> * -> *) where arr :: (b -> c) -> arr Nothing b c (>>>) :: arr i a b -> arr j b c -> arr (i :*: j) a c first :: arr i b c -> arr i (b,d) (c,d) Unfortunately, the following does not type-check with -XArrows and -XRebindableSyntax. diagram :: IArrow arr => arr f x fx -> arr g x gx -> arr (f :*: g) x gx diagram f g = proc x -> do fx <- f -< x gx <- g -< x returnA -< gx The error messages indicate that the type-checker is attempting to unify the types of f, g, returnA, and the entire proc block. However, the copy-and-pasted desugaring of that code *does* type-check (mutatis mutandi). This S data type is an example of an IArrow. data S i a b where SN :: ( a -> b ) -> S Nothing a b SJ :: s -> ((a,s) -> (b,s)) -> S (Just s) a b In terms of the S type, the objective of IArrow is to allow each "box in the diagram" to have its own state.

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testing ghc-7.8 rc2: linker issues
by Matthias Fischmann 14 Mar '14

14 Mar '14

hi, this time i am running 7.8 rc2 (binary for x64 on debian testing). after a successful '/usr/bin/cabal install cabal-install', i am running into different instances of this: | [...] | [25 of 25] Compiling Text.ParserCombinators.Parsec.Perm ( Text/ParserCombinators/Parsec/Perm.hs, dist/build/Text/ParserCombinators/Parsec/Perm.o ) | /usr/bin/ld: cannot find -lHSmtl-2.1.2-ghc7.8.0.20140228 | collect2: error: ld returned 1 exit status | Failed to install parsec-3.1.5 | cabal: Error: some packages failed to install: | network-2.4.2.2 depends on parsec-3.1.5 which failed to install. | parsec-3.1.5 failed during the building phase. The exception was: | ExitFailure 1 what makes me suspect this could be relevant to this list is that the symptoms are weirdly sporadic. my story: 1. cabal install string-conversions fails because -lHStext-1.1.0.1 cannot be found. 2. ghc-pkg unregister <a few packages> 3. cabal install network (which pulls text) => fails (see above) 4. cabal install string-conversions => works! i will read up on dynamic linking in ghc now. cheers, matthias

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haddock issue building ghc-7.8 from git
by Matthias Fischmann 14 Mar '14

14 Mar '14

Hi, When building from git (branch ghc-7.8 as of today), I run into a haddock issue because __GLASGOW_HASKELL__ appearently is not 709 on my system. Not sure whether this is a bug, and if it should go to trac/haddock or trac/ghc, so I decided to post it here. My "fix" is easy enough (even though I ran into other problems later, so I don't really know how well it works): | ~/src/ghc/utils/haddock/src/Haddock$ git diff | diff --git a/src/Haddock/InterfaceFile.hs b/src/Haddock/InterfaceFile.hs | index 924829d..19a742f 100644 | --- a/src/Haddock/InterfaceFile.hs | +++ b/src/Haddock/InterfaceFile.hs | @@ -76,14 +76,14 @@ binaryInterfaceMagic = 0xD0Cface | -- (2) set `binaryInterfaceVersionCompatibility` to [binaryInterfaceVersion] | -- | binaryInterfaceVersion :: Word16 | -#if __GLASGOW_HASKELL__ == 709 | +-- #if __GLASGOW_HASKELL__ == 709 | binaryInterfaceVersion = 25 | | binaryInterfaceVersionCompatibility :: [Word16] | binaryInterfaceVersionCompatibility = [binaryInterfaceVersion] | -#else | -#error Unsupported GHC version | -#endif | +-- #else | +-- #error Unsupported GHC version | +-- #endif | | | initBinMemSize :: Int thanks, matthias

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Where to find GHC.Types.D#_con_info
by Karel Gardas 14 Mar '14

14 Mar '14

Hello, I'm trying to debug few issues in SPARC NCG, now dealing with double floats issue. Always get 0.0 and while hunting this I've stepped over GHC.Types.D#_con_info which I'm not able to find in GHC sources but I guess it should be somewhere... Any idea where to look to see its code for reference? Thanks! Karel

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New validate failures
by Johan Tibell 14 Mar '14

14 Mar '14

Hi, Did something change in pretty-printing recently? I saw these new validate failures today: Unexpected failures: ghci.debugger/scripts break008 [bad stdout] (ghci) ghci.debugger/scripts break012 [bad stdout] (ghci) ghci.debugger/scripts break026 [bad stdout] (ghci) ghci.debugger/scripts hist001 [bad stdout] (ghci) ghci/scripts T5545 [bad stdout] (ghci) ghci/scripts ghci008 [bad stdout] (ghci) ghci/scripts ghci012 [bad stdout] (ghci) ghci/scripts ghci023 [bad stdout] (ghci) ghci/scripts ghci025 [bad stdout] (ghci) ghci/scripts ghci026 [bad stdout] (ghci) ghci/scripts ghci055 [bad stdout] (ghci) Two example stdout changes: --- ./T5545.stdout 2014-03-13 09:48:23.000000000 +0100 +++ ./T5545.run.stdout 2014-03-13 21:11:32.000000000 +0100 @@ -1,2 +1,2 @@ -($!) :: (a -> b) -> a -> b -- Defined in 'Prelude' +$! :: forall a b. (a -> b) -> a -> b -- Defined in 'Prelude' infixr 0 $! *** unexpected failure for T5545(ghci) --- ./ghci008.stdout 2014-03-13 09:48:23.000000000 +0100 +++ ./ghci008.run.stdout 2014-03-13 21:12:20.000000000 +0100 @@ -32,5 +32,5 @@ -- Defined in 'GHC.Float' instance RealFloat Float -- Defined in 'GHC.Float' instance RealFloat Double -- Defined in 'GHC.Float' -Data.List.isPrefixOf :: Eq a => [a] -> [a] -> Bool +isPrefixOf :: forall a. Eq a -> [a] -> [a] -> Bool -- Defined in 'Data.List' *** unexpected failure for ghci008(ghci)

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Should we always inline newByteArray#?
by Johan Tibell 13 Mar '14

13 Mar '14

Hi all, After some refactoring of the StgCmmPrim, it's now possible to have both an inline and an out-of-line (in PrimOps.cmm) version of the same primop. Very soon (#8876) we'll have both an inline and an out-of-line version of newByteArray#. The inline version is used when the array size is statically known and commons up the allocation with the normal heap check. The reason to have both versions is that we don't want to increase code size to much (by inlining a primop which implementation is large) unless we know that there's a benefit in doing so. However, the newByteArray# implementation is one function call (to allocate) followed by three stores (to the closure header). Perhaps, that's small enough to always inline? It would save one function call for each call to newByteArray#. Anyone have any thoughts on whether always inlining would be a good idea? -- Johan

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[PATCH] sync-all: Skip END actions on exceptions
by Florian Weimer 13 Mar '14

13 Mar '14

The instructions at <https://ghc.haskell.org/trac/ghc/wiki/Newcomers> were slightly outdated, and result in a rather confusing error messsage: $ ./sync-all --testsuite get Unrecognised flag: --testsuite at ./sync-all line 872. == Checking for old haddock repo == Checking for old binary repo == Checking for old mtl repo == Checking for old Cabal repo == Checking for old time from tarball ============================ ATTENTION! You have an old time package in your GHC tree! Please remove it (e.g. "rm -r libraries/time"), and then run "./sync-all get" to get the new repository. ============================ == Checking for obsolete Git repo URL $ The patch corrects the error message. I've removed the --testsuite flag from the wiki page as well.

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Building GHC on Windows
by Jan Stolarek 13 Mar '14

13 Mar '14

I'm trying to build GHC on 64-bit Windows 7. I installed Cygwin, GHC and cloned the main repo but when I run configure I get this error: configure: Building in-tree ghc-pwd checking for path to top of build tree... cygwin warning: MS-DOS style path detected: C:/cygwin64/home/tewi/head Preferred POSIX equivalent is: /home/tewi/head CYGWIN environment variable option "nodosfilewarning" turns off this warning. Consult the user's guide for more details about POSIX paths: http://cygwin.com/cygwin-ug-net/using.html#using-pathnames C:/cygwin64/home/tewi/head checking for gcc... C:/cygwin64/home/tewi/head/inplace/mingw/bin/gcc.exe checking whether the C compiler works... no configure: error: in `/home/tewi/head': configure: error: C compiler cannot create executables See `config.log' for more details I have gcc installed under Cygwin, but for some reason ./configure is looking for an in-tree compiler. I tried passing --with-gcc=/usr/bin/gcc to configure but with no result. Help? Janek

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